Yes, the scientific consensus right now is that the prefrontal cortex does not generally finish developing until the mid to late 20s, and this is the main locus of executive functioning. Perhaps according to some very narrow definition of “raw brain power” one could say, as TFA does, that this is all done in one’s teens - there seems to be consensus that IQ peaks around 19-20, though even short term memory (which I think would be unambiguously classed amongst “raw brain power”) is thought to peak in the mid 20s.